Road-killed snakes on the island of Cres (Croatia)

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1 BIHAREAN BIOLOGIST 11 (2): Biharean Biologist, Oradea, Romania, 2017 Article No.: e Road-killed snakes on the island of Cres (Croatia) Tamás TÓTH 1, Daniella BOKSAI 2, Csaba GÉCZY 3, Ármin MIHÁLYI 1, Rita TAKÁCS 4, Goran SUŠIĆ 5, Júlia VINCZEK 6, János GÁL 7, Miklós MAROSÁN 7, Balázs FARKAS 8, Alexandra BOKIS 1 and Miklós HELTAI 9 1. Zoological and Botanical Garden of the City of Budapest, P.O. Box 469, H-1371 Budapest, Hungary. 2. Wildlife Park Budakeszi, P.O. Box 88, H-2092 Budakeszi, Hungary. 3. Gyöngyvirág u. 3/a, H-1125 Budapest, Hungary. 4. Hauptplatz 6/8, A-2115 Ernstbrunn, Austria. 5. Ornithological station Rijeka, Institute of Ornithology HAZU, Ružićeva 5/2, Rijeka, Croatia. 6. Öko-Pract Kft., Kossuth u. 32, H-6400 Kiskunhalas, Hungary. 7. University of Veterinary Medicine, István u. 2, H-1078 Budapest, Hungary. 8. Bercsényi u. 21, H-2464 Gyúró, Hungary. 9. Institute for Wildlife Conservation, Szent István University, Páter Károly u. 1, H-2100 Gödöllő, Hungary. *Correspnding author, T. Tóth, truffoi@gmail.com Received: 27. May2017 / Accepted: 09. September 2017 / Available online: 05. October 2017 / Printed: December 2017 Abstract. The remains of 42 road-killed snakes belonging to six species collected on the island of Cres, Croatia in the framework of a 10-year long conservation cooperation between the Budapest Zoo and the Eko-centar Caput Insulae (Beli, Cres) are subjected to analysis. The main data of every individual and the ratio of each species represented in the sample are shown in tables. The species composition in the sample of dead snakes is compared with that reported in the literature for or observed personally by the authors in the same geographical area. The size classes most affected by vehicular traffic are revealed by statistical analysis. Finally, relying on literature data, an attempt is made to determine which road sections are the most dangerous to the snakes living on the island. Key words: Cres island, vehicular traffic, dead-on-road, found, snake. Introduction In recent years the northern part of the Adriatic Sea has become the focus of interest for tourists, and the bigger islands such as Krk, Lošinj and Cres are no exceptions either (Tóth et al. 2006). From the herpetological point of view, Cres is of particular interest because besides other reasons the 45th parallel north passes through the island, dividing its climate into Mediterranean and temperate climate zones (Balon et al. 2005). If we compare the human population density of Cres (406 km 2 ; appr inhabitants) to that of the neighboring islands of Krk (406 km 2 ; inhabitants) or Lošinj (77 km 2 ; 8500 inhabitants) it turns out that while the population density on Krk is 34 people/km 2 and 110 people/km 2 on Lošinj, it is merely 10 people/km 2 on Cres (Mavrović 1997, Balon et al. 2005). The herpetofauna of Cres has been the subject of several surveys (e.g., Bruno 1980, Sehnal & Schuster 1999, Rathbauer 2002, Tóth et al. 2006) and based on these investigations a total of 23 amphibian and reptile species are now known to occur with certainty on the island, while the presence of a few others (e.g., Bombina variegata, Hemidactylus turcicus, Tarentola mauritanica, Lacerta trilineata, Podarcis siculus, Natrix tessellata, Vipera ammodytes) remains unconfirmed. On Krk 28 (records of Tarentola mauritanica, Lacerta bilineata and Podarcis muralis need confirmation), on Lošinj 12 species have been sighted so far (occurrences of Lacerta trilineata and Eurotestudo hermanni are to be verified). While Krk is accessible via a bridge, Cres and Lošinj can be reached only by ferry. This fact as well as the lack of bigger hotels on the island of Cres impeded some of the tourist invasion and contributed to the preservation of natural values. However, in the last decade the infrastructure of Cres started to improve and the touristic improvements got under way again. While these improvements have a number of positive effects, they are shadowed by some worrysome subsequent developments. One of these events was that in 2012 the Eko Centar Caput Insulae Beli an institute inspired to protect the natural values of Cres, more precisely the nesting populations of Griffon Vultures Gyps fulvus had to leave the island and move its headquarter to the neighboring mainland (Starc 2001, Mackelworth et al. 2013, Sušić & Radek 2013, Batel et al. 2014). The renovation and modernization of the roads is a solicitous change from the conservational point of view though it is useful for the travelers, it is undoubtedly harmful to the local fauna. The newly made carriageways are missing wildlife crossings, while between the opposite lanes and on their edges in total three high, parallel running concrete walls block the transition of the fauna living on the two sides of the road. On those road sections, where the mentioned concrete walls are lacking, the increased traffic means bigger danger to the local fauna, mainly to smaller vertebrates. The same problem elsewhere in the Mediterranean Region was also addressed in the works of Kambourova- Ivanova et al. (2012) and Vujović et al. (2015). The first paper reported that there were substantial differences in the distribution of dead-on-road (DOR) vertebrates along sections of secondary vs. primary roads in Bulgarian Thrace. Not counting migrating frogs killed in the breeding season the largest number of vertebrates run over on secondary roads were birds, and on primary roads reptiles and amphibians. The authors concluded that among reptiles the proportion of snakes surpassed 50% in both categories (62.5% secondary, 68.5% primary road). Vujović et al. (2015) investigated the effects of fire and vehicular traffic on a population of Hermann s Tortoises Eurotestudo hermanni along a speedway in Montenegro (Crna Gora). Results showed that the number of adult individuals greatly surpassed that of sub adults fallen victim to vehicular traffic. It was also shown that the installation of rock fall netting reduced the number of run

2 Road-killed snakes on the island of Cres (Croatia) 89 overs but at the same time constituted a deadly trap for tortoises seeking escape from fire. Similar studies have also been published in the neighboring Romania. Thus, for example, Ciolan et al. (2017) found a total of 48 taxa (most of which were from invertebrates) between the dead animals on a 4.5 km road section, between March and October Their study also pointed out, that most of the animals fell victim to transport in the spring, and in the summer this figure dropped and rose again in the autumn. A similar result was obtained by Cicort-Lucaciu et al. (2016), they found the dead individuals of 50 different taxa in two days, on three different secondary roads, due to the car traffic. In their case, invertebrates were also dominant. Both recent studies have shown that amphibians were presented in the largest number among the vertebrates, as previously described by Cicort-Lucaciu et al. (2012) too. On some occasions, between these carcasses also have specimens of species that offer new faunistic findings. Thus, for example, in September 2011, a flooded Eryx jaculus verified for the first time that the species occurred in Romania north of the river Danube (Covaciu-Marcov et al., 2012). Upon recognizing this problem employees of the Eko Centar and employees of the 10 years long collaborating Budapest Zoo & Botanical Garden wished to deal with it as well, alongside conducting basic botanical and zoological research. As part of the mentioned cooperation personnel of Budapest Zoo have taken part in basic zoological research on various islands of the Cres Lošinj Archipelago from 2002 on (Tóth et al. 2006, 2009a, 2009b, Sós et al. 2009), and have observed numerous snakes run over by cars, primarily on Cres. Thus, by analyzing literature data and collecting dead-onroad snakes we seeked to investigate which species, which genders and which size classes were the most affected by vehicular traffic on the island. By overviewing data from the literature we wished to establish whether the number of run over snakes increased in the past few years. In addition we wanted to determine which road sections were the most dangerous in this respect. Finally by collecting DOR specimens we hoped to verify the presence of species previously undocumented or unvouchered from the island. Material and methods The targeted collection of run over specimens was carried out between the 1 st of January 2010 and the 31 st of December 2012 and the corpses were stored frozen at the former headquarters of the Eko Centar Beli until the end of the research period. We also collected run over snakes occasionally prior to the mentioned research period, which were stored at the base of the Croatian partner as well, alongside specimens found by the local researchers and volunteers. Most of the collected specimens were found on roads between Beli and Cres, and between Cres and Merag, because the employees of both the Zoo and the Eko Centar mainly commuted in this region. Independently from this a smaller portion of the corpses were collected by volunteers in the southern part of the island, but unfortunately we could not get an accurate picture about exact locations, times and circumstances of the collection of some of these run over snakes. During data collection we recorded the weight (if it made sense), and the main body measurements of the snakes, and pictures were taken of every specimen. We could not find ecto- and endoparasites due to the state of the corpses; there were no eggs in the dead animals and we managed to identify the gender only in 8 cases in total. Stomach contents were found in two cases: at first we discovered a 360 mm ( mm) long Western Green Lizard Lacerta bilineata in the digestive system of an Eastern Montpellier Snake Malpolon insignitus. In the second case we recovered a well-digested adult Dalmatian Wall Lizard Podarcis melisellensis from the stomach of a 627 mm long Cat Snake Telescopus fallax. Measuring the lenght of the latter lizard was not possible due to its poor condition. In the next part of our work we try to make comparisons to the data extracted from various publications, during which we will compare, species by species, the ratio of snakes observed alive in the wild and run over as much as the available information allows it. This comparison implies that it is not necessarily the most frequently observed snake species that most frequently becomes victim to vehicular traffic. In the case of ratio differences between the two groups we will also make an attempt to reveal the possible reasons for these differences. In the following section of the present work based on the available data we try to determine those size limits of each species in which they fall victim to road traffic the most. To reach the above formulated goals we made statistical analyses as well, using the available data. At the end of our work a Table 4 summarizes the most endangered size categories species by species, regarding running over. The determination of the confidence interval is a method of statistical evaluation (Table 3), which is calculated with the help of the statistical estimator made from the sample. In the current case we worked on a 95% confidence level and with 5% error which are the most frequently used values in similar statistical examinations. Using both our own and other running over data found in the literature we also marked on a map (Fig. 1) those road sections where according to our present knowledge the snakes succumb to vehicular traffic in the largest numbers. Results Run over specimens of six out of the eight species that occur with certainty on the island were found on the roads (specimens of the Grass Snake Natrix natrix and the Smooth Snake Coronella austriaca were not found among the run over ones), numbering roughly 42 individuals. Unfortunately, most of these collected specimens were in a very bad state, many of them were incomplete, which made a thorough analysis difficult. Only five out of the 42 specimens were in such condition that made possible to collect tissue and organ samples from them; the obtained results from these samples will be published elsewhere, at a later time. After the data taking work, the corpses were handed over to the Herpetological Collection of the Hungarian Natural History Museum, where the conservation/fixation and storing of the still usable specimens were taken care of. Balkan Whip Snake Hierophis gemonensis Bruno (1980) found in 1974 two, whilst in 1975 one living specimen of this snake on the island, while Sehnal & Schuster (1999) reported that between they observed 7 living individuals on Cres, respectively two run over specimens in Rathbauer (2002) and his colleagues met this species as well here in 2002, on several occasions. According to these, they found them several times on the Merag Peninsula, on the road leading to Beli, along the tourist trail near Beli, and in the city of Cres. Beyond these they saw (presumably single) living specimens at the Merag Porozina Cres junction near Lake Vrana, in the gardens of Predošćica, respectively two individuals next to Hrasta, and further ones were found near Punta Križa and southeast of Osor as well. Apart from this, Rathbauer (2002) found a run over speci-

3 90 T. Tóth et al. Table 1. Hierophis gemonensis (H. g.) Elaphe quatuorlineata (E. q.), Zamenis situla (Z. s.), Malpolon insignitus (M. i.) and Telescopus falax (T. f.) specimens collected on the island of Cres and their measurements. Figure 1. Locations of snakes found run over on Cres based on literature data presented in Table 6 (Symbols: Hierophis gemonensis: green; Elaphe quatuorlineata: light blue; Zamenis situla: dark blue; Malpolon insignitus: red; Telescopus fallax: yellow; the red and green lines indicate Rathbauer s [2002] battlefield along the Belej Osor road section). men near Lake Vrana and claimed that several individuals fell victim to vehicular traffic daily on the Belej Osor road. Dieckmann (2004), based on his experiences in 2002, also declared that the species was common throughout the island but he did not mention run over specimens. Tóth et al. (2006) stated that between they themselves found this snake twice in Beli, as well as many other times along the Eco-Trail next to Beli, respectively on one occasion around the ruins of the Sveti Bartolomej monastery as live specimens. Apart from this they met this species DOR near the crossing of the roads toward Cres Merag Porozina, southeast of Lubenice, respectively on the road between Punta Križa and Osor (Fig. 2). However, these individuals are included in the data shown in the Table 1. Identifier Total lenght in mm Comment H. g Back bodypart is missing H. g H. g male H. g H. g male H. g H. g H. g male H. g E. q E. q E. q E. q male E. q E. q E. q Z. s Z. s Z. s M. i M. i End of the tail is missing M. i M. i M. i M. i M. i M. i M. i male M. i female M. i female M. i M. i M. i M. i The corpse is not complete M. i T. f T. f The corpse is not complete T. f T. f T. f T. f The head is missing ing individuals of the species on the island between 1994 and In contrast, Rathbauer (2002) and his collagues found five living four-lined snakes on Cres in 2002, while Dieckman (2004) observed several live young and subadult specimens on this island, likewise in Mayer (Wien, pers. com.) found an additional living individual of this species in 2002 in this area. On the contrary, Tóth et al. (2006) between 2001 and 2005 found two living and one run over specimen on the island (Fig. 2), though the DOR individual is included in the Table 1. Four-lined Snake Elaphe quatuorlineata Bruno (1980) saw and photographed a single living specimen in 1977, while Sehnal & Schuster (1999) found seven liv- Leopard Snake Zamenis situla Bruno (1980) found two living Leopard Snakes and a shedding in 1977 and in 1979 in this area, while Sehnal & Schus-

4 Road-killed snakes on the island of Cres (Croatia) 91 Figure 2. Run over young Elaphe quatuorlineata on Cres. ter (1999) saw four living specimens in total between 1997 and 1998 in the same area. Dieckman (2004) reported the observation of a single living specimen from his trip in 2002, respectively Mayer (Wien, pers. com.) also found another living one on Cres in the same year, while Tóth et al. (2006) found only one freshly run over individual on the island between 2001 and 2005 (Table 1). Aesculapean Snake Zamenis longissimus On Cres we found a single, run over specimen of this species in a rather good state, which had the following main parameters: body weight 265 g, total length 1104 mm, girth around the neck 40 mm, girth in the middle of the body 73 mm. An outstanding feature of the mentioned snake was the strongly melanistic colouration. Bruno (1980) found only a single living (148 cm long) specimen from this species on Cres in 1977, while Rathbauer (2002) and his colleagues recorded three living individuals on the island. Mayer (Wien, pers. com.) found here further two living Aesculapean snakes in Eastern Montpellier Snake Malpolon insignitus Bruno (1980) found a shedding on the island in 1977, whereas in 1979 he found both a run over and a living specimen of this back-fanged colubrid. Sehnal & Schuster (1999) observed six living individuals between 1994 and 1998, while in 1998 they found a run over specimen. Rathbauer (2002) reported that with his collaguages they found only run over or badly injured specimens of this species on Cres in Already on the day of arrival to the island three run over individuals were found by the participants of the expedition, as well as they observed a living one. Hereafter they found one more run over and at least three living snakes, though above these data the author declares that the Belej Osor road during the Pentecostal festivities looked like a battlefield, where more run over specimens of this species could be seen daily. Tóth et al. (2006) found two subadult and one adult (Fig. 3) run over individual on the island, which are included in the Table 1. Cat Snake Telescopus fallax Sehnal & Schuster (1999) found only in 1997 one living specimen on the island, while Tóth et al. (2006) recorded one run over individual here in 2005, which is also included in the Table 1. Figure 3. Run over Malpolon insignitus specimen on Cres. The conclusion of the results with the help of statistical analysis The coefficient of variation expresses the ratio of the variation correlated to the mean (Table 2), namely that our data set in this case the size measurements of a species is how Table 2. Mean total lengths of run over snakes per species and the mean differing from the mean size (deviation). Species Variation coefficient (%) Mean Mean Hierophis gemonensis 40,45031* 544,22 220,14 Elaphe quatuorlineata** 10,02 432,83 43,38 Zamenis situla 15,90 528,33 84,02 Malpolon insignitus 29,89* 771,71 230,66 Telescopus fallax 13, ,99 closely represented by the mean of the data set. Thus whether we get a true picture of the mean size of the run over snakes based only on the mean, respectively how steady are the data collected by us. In optimal case the value is approximately 10%. In case it exceeds 30%, the mean does not describe our data set. In case of two species (Hierophis gemonensis and Malpolon insignitus) we marked with an asterisk (*) the value of the coefficient of variation, because in the case of the Hierophis gemonensis it exceeded the allowed 30% and in the case of the Malpolon insignitus it approximated that. Therefore in these two cases it is worth to ignore the obtained mean values. In short of skeletochronological examinations only the most endangered sizes presented in Table 3 can be given. The reasons for this are the gender and individual significant size differences of the specimens of the same age and species living in similar conditions (Pleguezuelos & Moreno 1989). Further, it should be noted that the mean measurements of the different populations belonging to the same species may show a significant deviation, which can be especially true in the case of comparing the mainland and island populations. We can find such differences between mainland (70 80 cm) and island (40 55 cm) specimens of the Sand Viper Vipera ammodytes as well (Wettstein 1953, Biella 1983, Schweiger 1992), which differences can be attributed to the meager food resources available to island populations (Brodmann 1987).

5 92 Figure 4. The percentage of run over snakes on the island of Cres based on the 42 specimens examined by us. Table 3. The most endangered size categories of each species regarding running over, determined with the help of the confidence interval. We treated one significantly different specimen of Elaphe quatorlineata marked with double asterisk (**) as a prominent data in order to be able to determine the confidence interval correctly. Species Confidence interval (most affected sizes mm) Hierophis gemonensis Elaphe quatuorlineata** Zamenis situla Malpolon insignitus Telescopus fallax Discussion Only the Smooth Snake Coronella austriaca and the Grass Snake Natrix natrix were not represented among the run over specimens of the snake species known to occur with certainty on the island and the Dice Snake Natrix tessellata and the Sand Viper Vipera ammodytes the presence of which was considered dubious were not verified either from the material collected on Cres (see Bruno 1980, Tóth et al. 2006, Bonte 2012). Although the dispersal of the Dark Green Snake Hierophis carbonarius to this island from the neighboring Krk can be expected (Heimes 1993), for the time being we did not T. Tóth et al. find any evidence for its occurrence on Cres. In Table 4 we listed those locations cited in the literature where run over snakes were found on Cres. We marked on Figure 1 those points and routes to which the mentioned data are related as probably these sites are the most dangerous to the snakes living on the island. These road sections most likely pose a similar risk to the other members of the local fauna. It can be seen that in the 1970s Bruno (1980) found only one run over snake, eight living specimens and two shedding on the island, while Sehnal & Schuster (1999) in the 1990s found three dead specimens alongside 25 living ones. However, Rathbauer (2002) stated that in May on the Belej Osor road section more Hierophis gemonensis fell victim to the traffic every day according to the observations in 2002 he made together with his colleagues. Regarding the same road section in the same time period the same author says that for Malpolon insignitus this area is a real battlefield where many specimens succumb. Although the latter author does not give exact numbers of the observed snakes, it is known that he saw at least 23 living ones, coupled with the findings of five run over snakes mentioned individually. Based on the presented data the number of run over snakes unequivocally seems to be increasing, which probably correlates with increasing vehicular traffic as a result of touristic boom. The conclusions derived from the map presentation can underpin the connection between the number of run over snakes and tourism, because although Cres is not an explicit touristic paradise just yet Lošinj, the island to the south of Cres is more frequented from this aspect as for more than a 100 year it is a well-known holiday resort and cure-center. Many tourists reach the island of Lošinj via ferry arriving at Merag and from there passing through Cres Belej Osor they reach the bridge between the two islands, therefore this may also have something to do with the fact that most run over snakes were found on this route. In addition to this it should be noted that the represented run over snakes in the Table 4 with one exception all fell victim to vehicular traffic in May and June, due to the fact that for the researchers these months are the optimal ones Table 4. The locations of the snakes found run over on Cres and the months of the events based on literature data. No. Species Location Month Reporter 1. H. gemonensis Merag-peninsula, south of Sveti Vid June Shenal & Schuster (1999) 2. H. gemonensis West of Srem June Shenal & Schuster (1999) 3. H. gemonensis Area of Vrana-lake, towards the sea from Vrana May Rathbauer (2002) 4. H. gemonensis Crossing of Cres-Merag-Porozina May Tóth et al. (2006) 5. H. gemonensis Next to Lubenice, the region of Podolić June Tóth et al. (2006) 6. H. gemonensis 7,2 km from Punta Križa, towards Osor June Tóth et al. (2006) 7. E. quatuorlineata North of Cres June Tóth et al. (2006) 8. Z. situla Beli May Tóth et al. (2006) 9. M. insignitus Near Osor on the road towards Cres August Bruno (1980) 10. M. insignitus Betwen Belej and Srem June Shenal & Schuster (1999) 11. M. insignitus Road leading towards Merag May Rathbauer (2002) 12. M. insignitus Road leading towards Merag May Rathbauer (2002) 13. M. insignitus Road leading towards Merag May Rathbauer (2002) 14. M. insignitus Edge of the city of Cres May Rathbauer (2002) 15. M. insignitus 11,3 km from Punta Križa towards Osor June Tóth et al. (2006) 16. M. insignitus 0,5 km north of Cres June Tóth et al. (2006) 17. T. fallax Cres-Merag-Porozina crossing May Tóth et al. (2006)

6 Road-killed snakes on the island of Cres (Croatia) 93 Figure 5. Population density on the three biggest islands of the Kvarner Gulf and the number of amphibian and reptile species present on these islands. for data collection. On one hand the mentioned time period is still within the breeding and pre-estivation active period of native snakes; on the other hand attention should be payed to the fact that in these months tourism and vehicular traffic do not reach their peak yet. During late summer road traffic probably increases above the level of May and June. However, in this time period it is most likely that the activity of the snakes will decrease with the increase of temperature. Based on the available data the high ratio of the two opistoglyphous species is prominent in the entire examination material. Based on our own experiences living specimens of Malpolon insignitus can rarely be encountered on Cres, while among the run over carcasses the species stands out with the highest proportion: about 38% (16 individuals) (see Figure 4), for which we know no explanation. On the other hand, in the case of the Telescopus fallax it can be explained by its nocturnal habits that only one living specimen is mentioned in the literature, while in our examination material the species was represented by 6 specimens (14%). Beyond this it is worth to mention that determining the gender among the corpses was possible only in eight specimens, with five being males and three being females. Although the small sample size does not allow for thorough conclusions, it is conceivable that the bigger ratio of males among run over specimens is due to their increased activity in the breeding season, as pointed out by Schweiger (1992). Acknowledgments. The authors would like to thank the Budapest Zoo and its director general, Miklós Persányi who made the trips to Croatia possible, as well as the volunteers of the Eko-Centar Cres who had facilitated our work. We are additionally grateful to the Ministry of Culture of the Republic of Croatia for authorizing the collection of dead snakes and their transportation to Budapest. We also would like to thank our fellow-travelers who assisted us in the field: Ildikó Czigány, Bálint Halpern, Andrea Keszi, Tibor Kovács, Levente Moharos, Zoltán Molnár, Viktor Molnár, Endre Sós, János Tardi, and Vince Zsigmond. References Balon, B., Braškić, I., Galjanić, V., Manzoni, R., Sokolić, J. (2005): Lošinj. Turistička naklada d. o. o., Zagreb. [in German] Batel, A., Basta, J., Mackelworth, P. (2014): Valuing visitor willingness to pay for marine conservation: the case of the proposed Cres Lošinj Marine Protected Area, Croatia. Ocean & Coastal Management 95: Biella, H.-J. (1983): Die Sandotter (Neue Brehm Bücherei Nr. 558), Ziemsen, Wittenberg Lutherstadt. [in German] Böhme, W. (1993a): Elaphe longissima (Laurenti, 1768) Äskulapnatter. pp In: Böhme, W. (ed.): Handbuch der Reptilien und Amphibien Europas. Band 3/1. Schlangen (Serpentes) I. Aula, Wiesbaden [in German] Bonte, C. (2012): Affirmation of Coronella austriaca (Laurenti, 1768) on the island of Cres, Croatia. Herpetology Notes 5: Brodmann, P. (1987): Die Giftschlangen Europas und die Gattung Vipera in Afrika und Asien. Kümmerly - Frey, Bern (in German). Bruno, S. (1980): L erpetofauna delle isole di Cres, Trstenik, Plavnik e Krk (Kvarner, Jugoslavija). Atti del Museo civico di storia naturale di Trieste 31 (3): [in Italian, English summary] Cicort-Lucaciu, A.S., Covaciu-Marcov, S.D., Bogdan, H.V., Sas, I. (2012): Implication upon Herpetofauna of a Road and its Reconstruction in Carei Plain Natural Protected Area (Romania). Ecologia Balkanica 4(1): Cicort-Lucaciu, A. S., Sas-Kovács, I., Covaciu-Marcov, S.D. (2016): Non road human influence upon road mortality on three secondary roads in the Vâlsan River protected area, Romania. Muzeul Olteniei Craiova. Oltenia. Studii şi comunicări. Ştiinţele Naturii 32(2): Ciolan, E., Cicort-Lucaciu, A.S., Sas-Kovács, I., Ferenti, S., Covaciu-Marcov, S.D. (2017): Wooded area, forest road-killed animals: Intesity and seasonal differences of road mortality on a small, newly upgraded road in western Romania. Transportation Research Part D 55: Covaciu-Marcov, S. D., Ferenti, S., Cicort-Lucaciu, A. S., Sas, I. (2012): Eryx jaculus (Reptilia, Boidae) north of Danube: a road-killed specimen from Romania. Acta Herpetologica 7(1): Dieckmann, M. (2004): Die Lacertiden der Kvarner-Inseln Cres und Lošinj / Kroatien. Die Eidechse 15 (1): [in German, English summary] Heimes, P. (1993): Coluber viridiflavus Lacepède, 1789 Gelbgrüne Zornatter. pp In: Böhme, W. (ed.): Handbuch der Reptilien und Amphibien Europas. Band 3/1. Schlangen (Serpentes). I. Aula, Wiesbaden. [in German] Kambourova-Ivanova, N., Koshev, Y., Popgeorgiev, G., Ragyov, D., Pavlova, M., Mollov, I., Nedialkov, N. (2012): Effect of traffic on mortality of amphibians, reptiles, birds and mammals on two types of roads between Pazardzhik and Plovdiv region (Bulgaria). Acta Zoologica Bulgarica 64(1): Mavrović, N. (1997): Cres & Lošinj: Insel, Eilande und Riffe. Tisak Trebotić, Zagreb. [in German] Mackelworth, P., Holcer, D., Fortuna, C. M. (2013): Unbalanced governance: the Cres-Lošinj Special Marine Reserve, a missed conservation opportunity. Marine Policy 41: Pleguezuelos, J.M., Moreno, M. (1989): Folidosis, biometria y coloración de ofidios en el SE de la Península Ibérica: Malpolon monspessulanus (Hermann). Revista Española de Herpetología 3(2): [in Spanish, English summary] Rathbauer, F. (2002): Feldherpetologische Exkursion nach Cres. ÖGH-Aktuell 10: [in German] Schweiger, M. (1992): Die Europäische Hornotter Vipera ammodytes (Linnaues, 1758). Teil 1: Systematik, Ökologie und Lebensweise. Herpetofauna 14(77): [in German, with English abstract] Sehnal, P., Schuster, A. (1999): Herpetologische Beobachtungen auf der Kvarnerinsel Cres, Kroatien. Ergebnisse von fünf Exkursionen. Herpetozoa 12(3/4): [in German, with English abstract] Sós, E., Molnár, Z., Tóth, T., Molnár, V., Susić, G. (2009): Horvát magyar együttműködés a fakó keselyű védelme érdekében [Hungarian Croatian cooperation for the protection of Griffon Vultures]. Heliaca 7: [in Hungarian, with English summary] Starc, N. (2001): Managing island development: the Croatian case. Sociologija sela 39(1/4): Sušić, G., Radek, I.V. (2013): Vulture status and conservation in Croatia. pp In: Andevski, J. (ed.): Vulture Conservation in the Balkan Peninsula and Adjacent Regions. 10 years of research and conservation. Vulture Conservation Foundation (VCF). Tóth, T., Grillitsch, H., Farkas, B., Gál, J., Sušić, G. (2006): Herpetofaunal data from Cres Island, Croatia. Herpetozoa 19 (1/2): [in English, with German abstract] Tóth, T., Farkas, B., Géczy, Cs., Sós, E., Halpern, B., Molnár, Z. (2009): Herpetofaunal data from Ilovik and neighboring islets (Cres-Lošinj Archipelago, Croatia). Herpetozoa 22(1/2): Tóth, T., Géczy, Cs., Sós, E., Molnár, Z. Halpern, B. (2009): Further data on the herpetofauna of Lošinj Island, Croatia. Herpetozoa 21(3/4): 192. Vujović, A., Iković, V., Golubović, A., Đorđević, S., Pešić, V. Tomović, L. (2015): Effects of fires and roadkills on the isolated population of Testudo hermanni Gmelin, 1789 (Reptilia: Testudinidae) in Central Montenegro. Acta Zoologica Bulgarica 67(1): Wettstein, O. (1953): Herpetologia aegaea. Sitzungsberichten der Österreichischen Akademie der Wissenschaften, Mathematischnaturwissenschaftlichen Klasse, Abteilung I. Wien 162(9/10): [in German] *****